Architects: PLANT Architect, Perkins&Will: PLANT Architect & Perkins+Will Canada
Text description provided by the architects. The Podium Roof Garden is the first transformation in the competition-winning scheme “Agora Theatre” – the Nathan Phillips Square Revitalization. This 3-acre upper-level component of Viljo Revell’s 1965 iconic and visionary City Hall and multi-level public square in Toronto was originally conceived as a ceremonial public space, reached via a giant sculptural ramp. The space was never successful at attracting the public – it was a grim, empty, three acres of concrete that has been closed for well over a decade. The Podium Roof Garden re-conceives this upper level as a public park integrated with the elevated walkway system, and while respecting the complex’s heritage status, reopening it to the public as a truly engaging 21st Century space.
Although it is the largest publicly accessible green roof in Canada providing a plethora of technical environmental benefits, the Podium Roof Garden is designed as a vast garden park which bears close scrutiny of its complex color and textural mosaic; is structured to closely reveal the compelling form and texture of the buildings, and provides plenty of spaces for strolling, lingering, intimacy and gathering. Simultaneously, it provides a compelling graphic legibility from the surrounding high-rise buildings.
The park consists of a sedum and perennial mosaic perimeter garden, a sparkling black granite paved courtyard that frames the Council Chamber, and a café deck that occupies the prow. The garden is a journey around the centrally located close-knit ensemble of the council chamber and towers. Inspired in part by Paul Klee’s Polyphony, it is planted with a complex mix of 23 species of sedums inter-planted with 46 species of grasses, alliums and bulbs with the colors subtly shifting and progressing from brighter yellows and oranges in the SW to reds and purples in the NE – responding to shade and wind conditions created by the towers. A wide walk runs around the perimeter and another runs tight to the base of the towers-Torontonians are just discovering after 45 years that the towers are clad in Carrara marble! Cross walks join these two circuit walks with quiet seating areas nestled among the plants. Bench lighting draws visitors into the garden at night.
The half kilometre walk reveals the passage of time at different scales. The shade structures mark the movement of the sun over the course of the day, their shadows aligning with benches at specified hours from 10am-2pm. The progression of plant and blossom colors follows the progressive circuit and includes something new blooming in different parts of the garden from April to October, marking seasonal change. The initial garden layout is rigid, but the plants will shift and move from the abstract geometry to a more Fauvist set of drifts as the years pass.
The black granite of the courtyard recalls Revell’s original reflecting pool (removed early on due to leaks) and with its animating light sticks, provides spill out from the wedding chapel and future municipal museum, and arts programming day and night. The prow supports large gatherings and is pre-plumbed for a future food kiosk. The large raised tree planter with its 3 Kentucky Coffee Trees (mature height 40+’) will provide shade, and finally beckons people from the main square to come and enjoy their new park.